Plastics are divided up into thermoplastics, thermosetting plastics and elastomers

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Topic of the Month: May 2015 (Background Information)

Plastics are divided up into thermoplastics, thermosetting plastics and elastomers

Major features of plastics are their technical properties, such as mouldabiliity, hardness, elasticity, breakage resistance, temperature resistance, heat distortion resistance and chemical resistance, which can be varied widely by the choice of macromolecules and manufacturing processes and – in most cases – by incorporating additives. As far as their physical properties are concerned, plastics can be divided up into three main groups: thermoplastics, thermosetting plastics and elastomers.

Thermoplastics (based on the ancient Greek words θερμός thermós = warm, hot and πλάσσειν plássein = form, mould), also known as plastomers, are plastics that can be moulded in a specific temperature range (thermoplastic). This process is reversible, i.e. it can be repeated as often as required by cooling and reheating to the molten state, unless what is known as thermal decomposition of the material begins due to overheating. This is what distinguishes thermoplastics from thermosetting plastics and elastomers. Another unique feature is that thermoplastics can be sealed.

Thermosetting plastics are plastics that cannot be moulded any more after they have cured. Thermosetting plastics are hard, glassy polymer materials that are permanently cross-linked three-dimensionally via chemical main valence bonds. The cross-linking takes place during the blending of upstream products with branched junctions and is activated either chemically at room temperature with the help of catalysts or thermally at high temperatures.